Analytics: use a site-tag list (open-telemetry#1529)

Author: chalin

config.yaml

@@ -54,6 +54,7 @@ params:
   github_repo: https://github.com/open-telemetry/opentelemetry.io
   github_branch: main
   gcs_engine_id: bde3d634eca9cd335
+  googleAnalytics: "G-QZHM7YEG07, UA-154693307-1"
 
   ui:
     footer_about_disable: true

layouts/partials/google-analytics.html

@@ -1,16 +1,16 @@
 {{/* Global site tag (gtag.js) - Google Analytics */ -}}
 
-{{ $ua_id := "UA-154693307-1" -}}
-{{ $ga4_id := "G-QZHM7YEG07" -}}
-{{ $ga_id := $ga4_id -}}
+{{ with .Site.Params.GoogleAnalytics -}}
 
-<script async src="https://www.googletagmanager.com/gtag/js?id={{ $ga_id }}"></script>
+{{ $ga_ids := split . ", " -}}
+
+<script async src="https://www.googletagmanager.com/gtag/js?id={{ index $ga_ids 0 }}"></script>
 <script>
   window.dataLayer = window.dataLayer || [];
   function gtag(){dataLayer.push(arguments);}
   gtag('js', new Date());
-
-  gtag('config', '{{ $ga_id }}');
-  gtag('config', '{{ $ua_id }}');
+  {{ range $ga_ids }}
+  gtag('config', '{{ . }}');
+  {{- end }}
 </script>
-{{- /**/ -}}
+{{- end -}}